If you are up for the challenge FREE HAND it like the image below.
Ok enough examples here are the steps...
1. Print out a square grid and tape it on the back of your canvas or draw one on the back with pencil. The grid can be small or large depending on how much time you are willing to put the cross stitching in. Usually the smaller the better it looks.
2. Lightly color in the square that will create the letter or words that you decided on.
3. Paint the front side of your canvas or cover it with fabric.
4. Poke a hole in all four corners of the square you colored with a needle, awl, or just something strong enough to poke through the canvas.
5. Now you are ready to start your cross stitching! Make sure you tie a tight enough knot so the thread doesn't slip through. You can also glue the end of the knot onto the canvas just to make sure it stays. When you are done do the same to the other end and knot it then glue it down.